MOGADISHU (Reuters) - A fighter jet struck a rebel base near the militant-bastion port city of Kismayu on Sunday, as Kenyan and Somali troops edged closer to another town hoping to strike a quick blow against al Shabaab.
The al Qaeda-linked rebels, blamed by Nairobi for several kidnappings of foreigners on Kenyan soil, pose a significant security threat to the Horn of Africa region and Nairobi launched an air-and-ground offensive against them a week ago.
The rebels have reinforced their defences in the town of Afmadow, a strategic transit point for goods trafficked illegally through Kismayu, al Shabaab's centre of operations.
Somalia's Western-backed troops say the aim of the operation is to rid Kismayu of the militants, which if achieved, would wipe out their base for logistics and recruitment.
"A jet bombarded an al Shabaab base near the port. It dropped a huge shell, flew past, came and then dropped another shell," Kismayu resident Mahmoud Hassan told Reuters.
"The whole town shook. We've never heard anything like it. Everyone ran away," he said.
A labourer at the harbour said the militants had ordered people to run to their homes.
"Al Shabaab fighters deserted the port but besieged the areas around the base," Hared Ali told Reuters.
An al Shabaab official who declined to be named said a Kenyan jet had struck two bases in Kismayu.
"There were no casualties. We fired at the plane after the second bombardment and it has not come back," the senior official told Reuters from southern Somalia.
The Kenyan military said a French naval gunship had bombarded the town of Kuday, south of Kismayu on Saturday.
General Yusuf Hussen Dhumal, commander of Somali government troops near Afmadow, told Reuters the town of Qoqani had been captured and they were heading to Afmadow and then Kismayu.
"Our troops in Taabto and Hayo have also moved near Afmadow and are just 7 km away. We wish in the coming two days to reach Afmadow ... Kenyan convoys are also with us," he told Reuters.
Residents said convoys of armoured vehicles and trucks carrying weaponry, food supplies and tents were seen leaving four military camps in Isiolo in northern Kenya on Friday and heading towards the border.
Kenya says it has not encountered any resistance from the rebels and that the militants are on the run and getting weaker, but any attempt to take Afmadow, where the rebels have massed and dug trenches, may result in a significant ground battle.
Kenya is the latest of Somalia's neighbours to intervene militarily in a country that has not had an effective government for the last 20 years. The militants have vowed to bring "flames of war" into Kenya if Nairobi refuses to withdraw its troops.
The threat of reprisal prompted the U.S. embassy in Kenya to warn its citizens of a possible "imminent threat," with attacks possibly targeting prominent Kenyan facilities and places where foreigners tend to gather like malls and night clubs.
The rebels have proven capable of carrying out large-scale attacks within and outside Somalia, and have put up stiff resistance against African Union (AMISOM) and government troops in the capital.
Earlier this week, AU and government troops launched a battle to force the militants out of Daynile district, one of the few pockets under al Shabaab control. At least 10 peacekeepers were killed in the battle.
Al Shabaab said they had killed more than 70 peacekeepers from the African force, which says the assertion is propaganda.
On Saturday, a suicide bomber targeted a convoy of four AMISOM vehicles in Mogadishu, wounding three peacekeepers, the force's deputy spokesman Prosper Hakizimana told Reuters. One of the vehicles was damaged and the suicide bomber was killed.
Kenyan police have increased patrols on the country's northern border with Somalia, to prevent al Shabaab rebels from escaping into the East African country.
Kenya, East Africa's biggest economy, has won support from neighbouring countries for its operation which it launched on Sunday after four Western women were kidnapped in the past few weeks and taken into Somalia, damaging its tourism industry.
Additional reporting by Feisal Omar in Mogadishu; Noor Ali in Isiolo; Writing by Yara Bayoumy; Editing by Louise Ireland